A&P Chapter 3: Cells and Tissues

nucleus

Control center of the cell

Smooth Endoplasmic Reticulum

lipid metabolism

Rough Endoplasmic Reticulum

involved with protein system; membrane channel

plasma membrane

A selectively-permeable phospholipid bilayer forming the boundary of the cells

centrioles

a minute cylindrical organelle near the nucleus in animal cells, occurring in pairs and involved in the development of spindle fibers in cell division.

Peroxisomes

Produce hydrogen peroxide; detoxify harmful substances

Lysosomes

cell organelle filled with enzymes needed to break down certain materials in the cell

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

Golgi apparatus

stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum

Cytoskeleton

network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended

Ribosomes

site of protein synthesis

tight junctions

Membranes of neighboring cells are pressed together, preventing leakage of extracellular fluid

gap junctions

provide cytoplasmic channels between adjacent animal cells

desmosome

A general cell junction, used primarily for adhesion; allows movement

Microvili

finger like projections of the cell plasma membrane. the function is to increase surface area

Cilia

The hairlike projections on the outside of cells that move in a wavelike manner; arise from cytoskeleton

Flagella

whiplike tails found in one-celled organisms to aid in movement

Solute

A substance that is dissolved in a solution.

Solvent

the substance in which the solute dissolves

Glycoproteins

proteins that have carbohydrates covalently bonded to them; serve many functions

Glycocalyx

The external surface of a plasma membrane that is important for cell-to-cell communication; fuzzy area of carbohydrates.

nuclear enevelope

double membrane that surrounds the nucleus

Nucleoplasm

Fluid inside the nucleus

Chromatin

non replicating DNA

Chromosomes

threadlike structures made of DNA molecules that contain the genes; are defined during cell division

Nucleolus

Found inside the nucleus and produces ribosomes

aquaporin

water channel protein in a cell

simple diffusion

Diffusion that doesn't involve a direct input of energy or assistance by carrier proteins.

facilitated diffusion

process of diffusion in which molecules pass across the membrane through cell membrane channels

osmosis

diffusion of water

Filtration

movement of particles based on fluid/hydrostatic pressure

Exocytosis

release of substances out a cell by the fusion of a vesicle with the membrane.

Pinocytosis

Cell drinking

phagocytosis

A type of endocytosis in which a cell engulfs large particles or whole cells; cell eating

receptor-mediated endocytosis

The uptake of specific molecules based on a cell's receptor proteins; vesicular transport

active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference

cell cycle

The regular sequence of growth and division that cells undergo

Interphase

Cell grows, performs its normal functions, and prepares for division; consists of G1, S, and G2 phases

G1 phase

stage of interphase in which cell grows and performs its normal functions

G2 phase

stage of interphase in which cell duplicates its cytosol and organelles (specifically centrioles)

S phase

DNA replication

semiconservative replication

each new DNA molecule consists of one new strand and one old strand

Mitosis

cell division in which the nucleus divides into nuclei containing the same number of chromosomes

Cytokinesis

division of the cytoplasm

Prophase

Chromosomes become visable, nuclear envelop dissolves, spindle forms

Metaphase

Chromosomes line up in the middle of the cell

Anaphase

the third phase of mitosis, during which the chromosome pairs separate and move toward opposite poles

Telophase

phase of mitosis in which the distinct individual chromosomes begin to spread out into a tangle of chromatin; nuclear envelop redevelops; cytokinesis finishes

Transcription

synthesis of an mRNA molecule from a DNA template; takes place in the nucleus

Translation

Process by which mRNA is decoded and a protein is produced; takes place at the ribosome

mRNA

messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome

tRNA

transfer RNA; type of RNA that carries amino acids to the ribosome

rRNA

ribosomal RNA; type of RNA that makes up part of the ribosome

leading strand

the new complementary DNA strand synthesized continuously along the template strand toward the replication fork in the mandatory 5' to 3' direction

lagging strand

The strand that is synthesized in fragments using individual sections called Okazaki fragments

Cell Theory

The fundamental concept that all living organisms are composed of cells, which are the basic unit of life. It also states that all cells arise from pre-existing cells.

Generalized Cell

A type of cell that exhibits all the basic structures and functions common to various cell types, including the nucleus, cytoplasm, and cell membrane.

Fluid Mosaic Model

A model describing the structure of cell membranes, where various proteins float in or on the fluid lipid bilayer, allowing for flexibility and dynamic functions.

Hydrophilic

attracted to water; substance that interacts well with water molecules.

Hydrophobic

repellent to water; substance that does not interact well with water molecules.

Nuclear Pores

Protein complexes that regulate the transport of molecules across the nuclear envelope, allowing essential substances to enter and exit the nucleus.

Inclusion

A non-living substance within a cell, often storing nutrients or waste products and not bound by a membrane.

Transport Vesicles

Membrane-bound sacs that transport materials within a cell and between the cell and its environment.

Secretory Vesicles

Transport vesicles that carry proteins and lipids from the Golgi apparatus to the cell membrane for secretion.

Free Radicals

Unstable molecules that can damage cellular structures, leading to oxidative stress and potential cellular injury. Unpaired electrons

Microfilaments

are the thinnest filaments of the cytoskeleton, composed of actin, and are involved in cell shape, motility, and division.

Intermediate Filaments

are a class of protein filaments within the cytoskeleton that provide structural support and stability to cells, playing a key role in maintaining cell shape and resisting mechanical stress.

Microtubules 

are cylindrical structures made of tubulin proteins that are involved in maintaining cell shape, facilitating intracellular transport, and organizing the placement of organelles during cell division.

Fibroblast

a type of cell that plays a crucial role in connective tissue production and maintenance, responsible for synthesizing collagen and other extracellular matrix components.

Erythrocyte

a red blood cell responsible for transporting oxygen from the lungs to tissues and returning carbon dioxide to the lungs.

Intracellular Fluid

The fluid found within the cells of the body, essential for cellular processes and providing a medium for biochemical reactions.

Interstitial Fluid

The fluid that surrounds cells in tissues, acting as a medium for nutrient and waste exchange between blood and cells.

Concentration Gradient

a difference in the concentration of a substance across a space, driving the movement of molecules from areas of higher concentration to areas of lower concentration.

Pressure Gradient

The difference in pressure between two areas that influences the movement of fluids or gases, often driving diffusion or flow from high to low pressure.

Solute Pump

A mechanism that uses energy, often in the form of ATP, to transport solutes across a cell membrane against their concentration gradient.

Passive Transport

The movement of substances across cell membranes without the need for energy input, typically occurring via diffusion or osmosis.

Sodium Potassium Pump

A vital membrane protein that actively transports sodium out of and potassium into cells, utilizing ATP to maintain concentration gradients essential for cell function.

Vesicular Transport

The process of moving large molecules or particles into or out of cells using membrane-bound vesicles, which requires energy input.

Phagocytosis

A type of vesicular transport where cells engulf large particles or microorganisms, forming a phagosome that can fuse with lysosomes for degradation.

Pinocytosis

A form of vesicular transport where cells take in liquid and small solutes, forming tiny vesicles that facilitate nutrient absorption and cellular intake.

Cleavage Furrow

A indentation that occurs in the cell membrane during cytokinesis, signaling the beginning of cell division as the cytoplasm is divided between two daughter cells.

Gene

A unit of heredity made up of DNA that carries the information necessary for the synthesis of proteins and determines specific traits in an organism.

Codon

A sequence of three nucleotides in mRNA that encodes a specific amino acid or signals the termination of protein synthesis.

Anticodon

A sequence of three nucleotides in transfer RNA (tRNA) that pairs with a complementary codon in messenger RNA (mRNA) during protein synthesis.

Epithelial Tissue

A type of tissue that covers body surfaces, lines cavities and organs, and forms glands. It plays roles in protection, absorption, and secretion.

Apical Surface

The side of epithelial cells that faces the lumen or the outside of the organ, often involved in absorption and secretion.

Basement Membrane

A thin, fibrous layer that provides support and anchoring for epithelial tissues, separating them from underlying connective tissues.

Avascular

Lacking blood vessels, a characteristic of epithelial tissues that relies on diffusion for nutrient supply and waste removal.

Simple Epithelium

A single layer of epithelial cells that facilitates absorption, secretion, and filtration in various organs.

Stratified Epithelium

A type of epithelium consisting of multiple layers of cells that provides protection, primarily located in areas subject to abrasion such as the skin and the lining of the mouth.

Simple Squamous Epithelium

A single layer of flat cells that helps with diffusion and filtration, often found in areas like the alveoli of the lungs and lining of blood vessels.

Serous Membranes

Thin layers of tissue that line body cavities and cover organs, producing a watery serous fluid to reduce friction.

Simple Cuboidal Epithelium

A single layer of cube-shaped cells that functions in secretion and absorption, commonly found in kidney tubules and glandular tissues.

Simple Columnar Epithelium

A single layer of tall, column-like cells that aids in absorption and secretion, typically found in the lining of the digestive tract and uterus.

Goblet Cells

Specialized epithelial cells that secrete mucus, found in various mucous membranes of the body.

Mucosae

The mucous membranes lining various body cavities and internal organs, providing lubrication and protection.

Pseudostratified Columnar Epithelium

A type of epithelium that appears to have multiple layers due to varying cell heights but is actually a single layer. It often contains cilia and goblet cells, mainly found in the respiratory tract.

Stratified Epithelia

A type of epithelial tissue composed of multiple layers of cells, providing protection against abrasion and found in areas such as the skin and lining of the mouth.

Stratified Squamous Epithelium

A type of epithelial tissue featuring several layers of flat cells, offering protection against mechanical stress and pathogens, commonly found in the skin, esophagus, and vagina.